Hub and cylinder design for flywheel system for mobile energy storage

A flywheel assembly storing energy and rotatable in response to the rotation of a shaft, comprising:

• a first cylinder section fixedly connected to the shaft;
• a transition member having a constant stress intermediate region fixedly connected to said first cylinder;
• a flexible cylinder fixedly connected to said transition member;
• and
• an outer cylinder fixedly connected to said flexible cylinder at at least one point, wherein:
• said outer cylinder includes an innermost cylinder and an outermost cylinder;
• said innermost cylinder mechanically connects said flexible cylinder to said outermost cylinder;
• the shaft, said first cylinder, and said flexible cylinder are substantially coaxial;
• said innermost and said outermost cylinders comprise a first strength fiber and a second strength fiber, respectively;
• the respective strength of said first and second strength fibers is selected responsive to distance from the shaft;
• and
• a majority of the mass of the flywheel assembly is concentrated in said outer cylinder.

A flywheel assembly storing energy and rotatable in response to the rotation of a shaft, comprising:

• first means for storing a majority of the stored energy present in the flywheel assembly;
• second means operatively attached to said first means for following radial changes in said first means responsive to variations in applied centrifugal force;
• third means fixedly attached to said second means for providing a substantially constant stress at each point along a radial section between the shaft and said second means;
• fourth means for fixedly connecting said third means to the shaft,
• wherein:
• the first means includes innermost and outermost regions containing first and second strength fibers, respectively
• the respective strength of said first and second strength fibers is selected responsive to distance from the shaft;
• and
• the shaft and said first, second, third and fourth means are substantially coaxial.